Two types of Mg-Cu composition system graded density impactors used for complex loading （shock loading and quasi-isentropic compression） are designed by the elastic-plastic hydrodynamic method in this paper. Mixtures of metal powders in the Mg-Cu system are cast into a series of 17 and 25 uniform compositions ranging from 100% Mg to 100% Cu. The graded den- sity impactors are launched to the stationary 10 Ixm aluminum film and 12 mm LiF window targets by a two-stage light-gas gun in the National Key Laboratory for Shock Wave and Detonation Physics Research, Institute of Fluid Physics, CAEP, and the resulting wave profiles are measured with the DISAR system. Hydrodynamic simulation results are perfectly consistent with the experiments. Our work in this paper will set up a foundation for further research of controllable loading/releasing routes and rate experiments in the future.
BAI JingSongTANG MiLUO GuoQiangYU JiDongYUAN ShuaiDAI ChengDaWU QiangTAN Hua
采用Smagorinsky和Vreman亚格子尺度应力模型，发展了适用于可压缩多介质粘性流体和湍流大涡模拟的数值编码MVFT（Multi-Viscous—Fluid and Turbulence）。利用MVFT编码对某冲击波二次加载下的流体动力学界面不稳定性及其引起湍流混合进行了数值模拟，并和实验结果进行了比较，二者相吻合。Sma—gorinsky和Vreman亚格子尺度应力模型均是基于涡粘性假设，因此都是绝对耗散的模型，但是Vreman模型的耗散相对较小。从本文计算结果的对比可以看出，Vre—man模型的计算结果比Smagorinsky模型的结果要好。
The shock tube experiments of inclined air/SF6 interface instability under the shock wave with the Mach numbers 1.23 and 1.41 are conducted. The numerical simulation is done with the parallel algorithm and the multi-viscous-fluid and turbulence （MVFT） code of the large-eddy simulation （LES）. The developing process of the interface accelerated by the shock wave is reproduced by the simulations. The complex wave structures, e.g., the propagation, refraction, and reflection of the shock wave, are clearly revealed in the flows. The simulated evolving images of the interface are consistent with the experimental ones. The simulated width of the turbulent mixing zone （TMZ） and the displacements of the bubble and the spike also agree well with the experimental data. Also, the reliability and effectiveness of the MVFT in simulating the problem of interface instability are validated. The more energies are injected into the TMZ when the shock wave has a larger Mach number. Therefore, the perturbed interface develops faster.
Tao WANGJin-hong LIUJing-song BAIYang JIANGPing LIKun LIU
